Geometrics and the National Park Service Team for Archaeology Field Exploration

Jun 08, 2016 | Posted in Blog, News

Geometrics recently took part in a week long workshop hosted by the National Park Service (NPS) at Fort Gadsden Historic site in Apalachicola National Forest in Florida. Approximately 50 people attended this year and included archaeologists and students from throughout the country. Naiema Jackson from the Geometrics sales team demonstrated the benefits of using geophysics as an investigative tool in archaeology. Her demonstration included both lectures and site exploration using an OhmMapper TR2 with OhmLog Android application for measuring resistivity and a cart mounted gradiometer with the MagMonitor Android application to measure local deviations in the magnetic field.. The benefit of using OhmLog and MagMonitor Android applications is that data can be observed in real time, which allows the user to evaluate the data during collection and to plot the gridded raw data in a map view prior to processing. These features allow the user to know that they are collecting the highest quality data.

Fort Gadsden

The site contains the ruins of two forts, with British soldiers building the original fort out of sand during the War of 1812. This first fort was larger and a British stronghold, as it occupied a strategic spot along the Apalachicola River. The British left the fort in 1815, leaving behind over 300 “freed” African slaves and many Native Americans, who were helping the British hold the fort and who, until 1816, protected it from attacks.

Archaeologists using a Geometrics OhmMapper TR2 to measure variations in resistivity

The Fort was seen as a place of refuge for slaves seeking freedom and was given the name the “Negro Fort”. This was a threat to the US government; General Andrew Jackson ordered an attack on the fort in 1816. US Navy forces with the help of the Creek Indians, who were promised whatever they could salvage from the fort, bombarded the fort hitting the ammunition shed inside and causing an enormous explosion. It is said that this explosion could be heard in Pensacola, over 100 miles away. The explosion was devastating, and only about 30 people survived. In 1818 Andrew Jackson ordered that James Gadsden rebuild the fort, and was so impressed with it that he named the fort in honor of Gadsden. The fort was occupied on and off until the end of the American Civil War. Today, there are no standing structures on the site, though trees are cleared and there is some indication on the ground of where the structures stood.

A team explores the grounds of Ft. Gadsden using a Geometrics' cart mounted magnetometer